Integrated DEM Style

All landuse, natural, vegetaion and other areas are displayed together with the Digital Elevation Model (DEM). The DEM is computed by the OSM-3D DEMTileGenerator process and stored as multiple tile sets in the W3DS data base. Due to the complexity of the DEM computation, the tiles are not generated on demand, but always retrieved from the W3DS data base, which is updated periodically.
The sizes of the DEM tiles correspond with the tile sizes as defined by the OSM tile cache. That is, level 0 is covering the whole world, a level 16 tile represents just a small portion of approx. 611x611 meters, which can be shown at larger scales. With each level, the tile size is divided by 2 and the number is quadrupled. Currently, level 7 through level 16 are being processed. All map features that represent physical structures of the earth surface and that can be described by a distinctive surface structure, are rendered as part of the DEM. This applies also to linear features such as the road network, paths, railways, waterways, and such. In this case, a geometrical buffer (Hausdorff distance around the lines) is applied to them in order to display them as part of the DEM. The buffer width increases with the tile size, since otherwise, these features would quickly disappear in the distance if only the "original", i.e. estimated real width would be taken.

The following table summarizes all land coverage, natural, and road features that are currently extracted from OSM and served by the W3DS. The values in the Buffer / Tile Level columns indicate whether or not the feature is selected for the specific tile level. Zero values mean that the feature is selected although no buffer is applied, since it's a polygon feature. Positive values describe the buffer width in meters (to both sides of the line, thus the actual feature width is twice this value).